673. Syphilis Outbreak in Women Who Have Sex with Men in Japan: a Case-control Study in Tokyo, 2017-2018
Session: Poster Abstract Session: Public Health: Epidemiology and Outbreaks
Thursday, October 4, 2018
Room: S Poster Hall
Posters
  • 673 Syphilis Outbreak in Women_Shingo Nishiki.pdf (150.1 kB)
  • Background: In Japan, syphilis notifications have increased sharply, with Tokyo accounting for a third of all cases. Importantly, the increase in women has been remarkable, with the majority being women who have sex with men. We therefore conducted a prospective case-control study to evaluate correlates of recent syphilis infection among women in Tokyo.

    Methods: We employed a test-negative design case-control study among women who sought a syphilis test at a women’s health clinic in Tokyo, comparing socioeconomic status, medical history, and recent sexual behaviors/partnerships, between those who were diagnosed with recent syphilis infection based on clinical signs and serological test results (cases) vs. those who were nonreactive for the nontreponemal test (controls). Participants aged ≥20 years and sexually active in the past six months were recruited from June 2017 to March 2018 and completed a self-administered questionnaire. We described cases and assessed for correlates of recent syphilis infection based on odds ratios (ORs) and 95% confidence intervals (CIs).

    Results: A total of 524 women, composed of 60 cases and 464 controls, were enrolled. The median age was 23 years (range=20-54) among cases and 26 years (range=20-59) among controls. Of the 60 cases, 10 (17%) were current students and 3 (5%) had a history of syphilis; in the past 6 months, while 35 (58%) had engaged in commercial exchange of sexual practices, 14 (23%) had only one sex partner. Having lower educational attainment (OR=4.1; 95%CI=2.1-8.1), not being employed full-time (OR=3.1; 95%CI=1.8-5.5), and commercial exchange of sexual practices (OR=3.4; 95%CI=2.0-5.9) were associated with case status in univariate analysis. The association between case status and inconsistent condom use (relative to consistent condom use) during vaginal/anal sex in the past 6 months (OR=2.0; 95%CI=0.9-4.3) became stronger when restricted to women engaged in commercial exchange of sexual practices (OR=4.0; 95%CI=1.4-10.9).

    Conclusion: This was the first study to evaluate potential risk factors for recent syphilis infection among women in Japan. In light of these findings, we may need a multi-pronged approach to prevent and control syphilis, for both those engaged in commercial exchange of sexual practices and the general population.

    Shingo Nishiki, MD1, Yuzo Arima, M.P.H., Ph.D.2, Takuya Yamagishi, MD, PhD2, Takashi Hamada, MD3, Takuri Takahashi, Ph.D.2, Tomimasa Sunagawa, MD, PhD2, Tamano Matsui, MD, PhD2, Kazunori Oishi, MD, PhD2 and Makoto Ohnishi, MD, PhD4, (1)Field Epidemiology Training Program, National Institute of Infectious Diseases, Tokyo, Japan, (2)Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan, (3)Shinjuku Ladies Clinic, Tokyo, Japan, (4)Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan

    Disclosures:

    S. Nishiki, None

    Y. Arima, None

    T. Yamagishi, None

    T. Hamada, None

    T. Takahashi, None

    T. Sunagawa, None

    T. Matsui, None

    K. Oishi, None

    M. Ohnishi, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.